This invention relates to a unique trunnion mount for an axle assembly which allows the axle to pivot about a longitudinal axis of a vehicle.
A typical axle assembly includes first and second driven wheels which are rotated by a driveshaft through a main differential. The axle assembly includes an axle housing which encloses the main differential and extends along a central axis between the driven wheels. The axle can be mounted to a vehicle frame by various methods. Some axle housings include spring pads or other mounting pads, located on a top surface of the axle housing between the main differential and the driven wheels. Brackets, springs, and other suspension components are attached to the axle housing via these mounting pads for supporting the vehicle frame on the axle.
Other axles utilize a trunnion mount for mounting the axle assembly to a vehicle frame. A typical trunnion mount includes first and second mounts disposed on longitudinally opposite sides of the central axis near the main differential for supporting the axle housing on the vehicle. An axle with a trunnion mount allows rotation about a longitudinal axis of the vehicle.
Current trunnion mounts use bearings for the first and second mounts. Usually, the first mount is supported by tapered roller bearings mounted on the pinion bearing cage located near the input shaft to the main differential while the second mount, attached to the opposite side of the main differential, is a tapered roller bearing or a straight cylindrical bushing which supports a vehicle frame bracket. These bearings react to both radial and axial forces that occur during the operation of the vehicle as a result of the duty cycle and vehicle loading. Over time, these forces cause the bearings to wear and eventually they need to be replaced. These bearings are expensive and require regular maintenance.
It would be desirable to reduce the axial and radial loading on the bearings so that longer component life can be achieved. It would also be desirable to replace the tapered roller bearing with a less expensive component. Thus, there is a need for a trunnion mount comprised of components with a long service life and which are inexpensive and easily maintained.